“I know this will ruffle feathers,” he told me, after he returned to a Washington office that had been inundated with complaints. “But I wasn’t elected to get along with everybody in D.C. I was elected to make a difference. We need to protect our communities, not listen to the NRA.”

Moulton’s right, of course. At this point, when the mass murder of Americans is as common as hurricanes, gestures are totally obligatory and virtually meaningless. Moulton is right to insist that action on gun control will honor the dead and wounded far more than some ritualistic, token gesture that allows lawmakers to pretend they care about the victims of gunfire as they do nothing to prevent more of them.

The idea that a 64-year-old man could obtain an arsenal of military-style weapons and stockpile them in a room on the 32nd floor of a hotel to unleash automatic gunfire on 22,000 people enjoying a concert below is obscene. It is just as obscene that so many congressmen, many of them in the pocket of the NRA and the gun industry, believe their duty to their fellow Americans ends with a bowed head and a prayer.

What happened in Las Vegas and the next mass shooting and the next one and the one after that are inevitable because it is too easy to obtain weapons that should be the reserve of the military and highly specialized tactical police units, like the one from the Las Vegas Metropolitan Police that prevented an even worse slaughter.

Then again, what if it was worse? What if the body count was 100 or 200 or 300? Would it make a difference to a Congress that has held so many moments of silence over the years as to render such superficial reverence meaningless? If 20 dead kids in Connecticut changed nothing, why would hundreds dead in Vegas or anywhere else change something?

Moulton, no doubt, will be dismissed in some circles as a heartless, opportunistic pol, especially by Republicans and their media. That cynical assessment will be even easier to pitch now that Moulton is being touted as a possible presidential candidate for the Democrats in 2020.

But Moulton is being consistent, and his stance is genuine. Along with colleague Katherine Clark of Melrose, he refused to take part in a congressional moment of silence last year after what was, before Sunday, the worst mass shooting in modern US history, when an Islamist extremist opened fire in the Pulse nightclub in Orlando, killing 49. In a tweet, Moulton said, like the moment of silence after Orlando, performing one after Vegas “just becomes an excuse for inaction.”

By refusing to go along with the perfunctory moment of silence, Moulton is essentially taking a congressional knee. The NFL players who have knelt during the national anthem have done so precisely because, despite widespread popular disapproval, it brings attention to their concerns about racial inequality.

Moulton’s figurative taking a knee on the moment of silence for mass shooting victims is being done precisely because it brings attention to an inescapable truth: the callow, shameless refusal of the majority in Congress to enact any meaningful legislation that would make it harder for people like Stephen Paddock to get their hands on guns whose only utilitarian purpose is to rapidly kill human beings in massive numbers.

After Orlando, Moulton sought out like-minded Republicans and with them crafted a bipartisan gun control bill that would, at a minimum, insist on background checks for all gun purchases. House Speaker Paul Ryan and the rest of the Republican leadership would have none of it. Moulton said he will try to craft a new bill with bipartisan support.

“Sadly,” he said, “the reality here with Speaker Ryan is that it takes moments like this to restart the discussion.”

The rat-a-tat-tat of automatic gunfire, captured by cellphone videos from concertgoers in Las Vegas, sounded so strange, so foreign in the middle of an American city. It’s a sound that Seth Moulton heard regularly during four tours of Iraq with the Marines. And it’s a sound that he knows, in his head and in his heart, belongs only on battlefields.

He will be roundly and loudly criticized for not taking part in a moment of silence. But the sound of automatic gunfire from Stephen Paddock’s rifles, and the anguished screams of the people who were listening to Jason Aldean when weapons of war rained down on them, cry out for action, not silence.